Since the Global Crisis, critics have questioned why regulatory agencies failed to prevent it. This column argues that the US Federal Reserve was aware of potential problems brewing in the financial system, but was largely unconcerned by them. Both Greenspan and Bernanke subscribed to the view that identifying bubbles is very difficult, pre-emptive bursting may be harmful, and that central banks could limit the damage ex post. The scripted nature of FOMC meetings, the focus on the Greenbook, and a ‘silo’ mentality reduced the impact of dissenting views.

The Global Crisis has intensified debates over the merits of financial innovation and the optimal size of the financial sector. This column presents a model in which the growth of finance is driven by the development of a financial innovation. The model can help explain the securitised mortgage debacle that triggered the latest crisis, the tech bubble in the late 1990s, and junk bonds in the 1980s. A striking implication of the model is that regulation should be toughest when finance seems most robust and when innovations are waxing strongly.